Entering (and losing) programs on HP 48

[Joe Horn]

(01-16-2021 06:43 PM)John Keith Wrote:  

(01-16-2021 01:59 PM)Dave Britten Wrote:  It doesn't say which flags enable Last Stack (Undo) and Last Command, which is weird. They should be somewhere in the Mode menu, though; I generally just leave them all on.

I've often wondered that myself. Is it possible that those modes are not part of the system flags at all?

Last Stack (UNDO) and Last Command are not controlled by any of the User RPL "system flags", so you can't turn them on or off using SF and CF. All things are possible, however, to System RPL programmers (e.g. UNDO_OFF in System RPL disables UNDO).